Conventionally, various methods have been used for a pneumatic tire (hereinafter referred to as a tire) to be mounted on a vehicle in order to suppress a rise in the temperature of the tire caused by travelling of the vehicle. In particular, in a heavy duty tire mounted on a truck, a bus or the like, a temperature rise is remarkable.
Therefore, in the tire with a groove portion extending in the tire circumferential direction and being formed in the tread portion of the tire, and a rib-shaped land portion partitioned by the groove portion, a tire is offered in which the groove bottom of the groove portion has a protrusion extending linearly from one groove wall to the other groove wall (Patent Literature 1).
With such a tire, when the tire rolls, the airflow passing through the inside of the groove portion becomes a turbulent flow due to the protrusion portion, and heat radiation from the tread portion is promoted by this turbulent flow. This makes it possible to suppress the temperature rise of the tread portion.